Looking at your code I would suggest that the problem is caused by dataframe styling. If you remove styling, then scrolling should work.
I already reported this bug to Datalore in March - https://datalore-forum.jetbrains.com/t/dataframe-styling/785. Seems like no solution yet.
@Marceli , @sergei is right (thank you!), unfortunately dataframe styling isn’t correctly supported at the moment. I just upvoted the corresponding issue in our tracker and will ask the devs to pay attention to it.
The fix has been deployed earlier this week, now the produced table should have a horizontal scrollbar if needed. Please let us know if you are still experiencing any problems there.